I was going to point you at the ThinkStation Tech Specs for P300 (found here). This page calls out the SATA ports as 2 x gen2 and 2 x gen3, with the eSATA port being gen2.

This conflicts with what you're reporting from the user guide, so I went and checked my internal spec listing, and that listing seems to confirm that all 4 SATA ports are gen3 and the eSATA port is gen3 as well (which somewhat confirms the user guide info). Typically we've used red SATA port color to indicate SATA3, so that also somewhat backs up the idea that the tech specs site is wrong.

So I'm tempted to believe there's a mistake in the tech specs on this and that everything might be gen3 on that board. If I can get a P300 booting, I'll try to check out the ports. Of course, if you already have everything in front of you, there should be no harm in hooking up your enclosure to the eSATA port and checking it out on your own as well.

On this particular board, I believe all 4 SATA and the eSATA port are routed off the AHCI side of the onboard Intel controller. So there should be no difference between the ports other than the fact that the eSATA port gets configured as a removable device in the registry.

I was looking at the M93p which I thought was the same, however M93p only has 3 x sata and 1 x esata.

I was physically looking at the P300 motherboard however there are a bunch of cables, in the same area some are for sata while another is for a multi-media drive, plus other wiring and cabling. Also a Nvidia Quadrom K4000 video adapter. I didn't want to remove all the cables and video card to expose the sata ports.

The OEM sata cables have clip in plugs whereas the aftermarket esata with plate and cable doesn't. When I plugged it into the mb's esata port it just slipped in and didn't snap or click in .. Very loose just sitting in the esata port without being secured.

SATA I (revision 1.x) interface, formally known as SATA 1.5Gb/s, is the first generation SATA interface running at 1.5 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 150MB/s.

SATA II (revision 2.x) interface, formally known as SATA 3Gb/s, is a second generation SATA interface running at 3.0 Gb/s. The bandwidth throughput, which is supported by the interface, is up to 300MB/s.

SATA III (revision 3.x) interface, formally known as SATA 6Gb/s, is a third generation SATA interface running at 6.0Gb/s. The bandwidth throughput, which is supported by the interface, is up to 600MB/s. This interface is backwards compatible with SATA 3 Gb/s interface.

SATA II specifications provide backward compatibility to function on SATA I ports. SATA III specifications provide backward compatibility to function on SATA I and SATA II ports. However, the maximum speed of the drive will be slower due to the lower speed limitations of the port.

The info I listed above is correct regarding what gen/speed each port is. The info you pasted from thinkstation-specs.com is wrong, and I'm working to get that updated.

The eSATA ports function just like normal SATA ports are are part of the same controller. The main difference is that eSATA has slightly different registry settings to mark it as a removable device, unlike standard SATA ports which are marked as non-removable. You still need to properly shut down the device within windows (from the taskbar) to safely remove it from the system.

Hotswap and removeable are not the same thing. eSATA is removable...yes....you must take action within the OS to stop the device before removing it though. Shutting down the OS is not required...you just need to stop the device within the OS via the taskbar.

Hot swap is something generally reserved for server usage (at least in terms of SATA). That's not supported on ThinkStation.